Background
Estimation techniques are crucial in econometrics, where systems typically strive to fit models to observed data. When such models exhibit nonlinear relationships with respect to their parameters, specialized estimation techniques, such as the nonlinear least squares estimator, become essential tools.
Historical Context
The concept of nonlinear least squares was developed in response to the limitations of linear least squares, especially in applications requiring more complex models where parameter relationships are not linear. This methodology has since found integral usage in various econometric frameworks and continues to be an area of significant research and application.
Definitions and Concepts
Nonlinear Least Squares Estimator (NLSE) - An estimator employed to handle parameter estimation problems where the first-order conditions for least squares are nonlinear functions of the parameters. The estimator operates by linearizing these conditions to solve for the model parameters, minimizing the sum of square deviations between observed and predicted values.
Major Analytical Frameworks
Classical Economics
The use of nonlinear least squares was not prevalent in classical economics as early models generally employed simpler linear relationships.
Neoclassical Economics
Nonlinear least squares estimation gained relevance in neoclassical economics with the need to model complex relationships and behaviors more accurately.
Keynesian Economics
Keynesian models, particularly those involving non-linear consumption functions or investment behavior, sometimes use nonlinear least squares for parameter estimation.
Marxian Economics
Nonlinear least squares is less frequently applied directly within traditional Marxian economics models but can be useful for empirical data analysis related to Marxian economic relationships.
Institutional Economics
Institutional economics might utilize nonlinear least squares estimation when exploring the effects of economic policies and institutions that impact economic behavior in non-linear ways.
Behavioral Economics
The complex models mapping non-standard utilities and psychological factors often use nonlinear least squares estimation to fit empirical data accurately.
Post-Keynesian Economics
Post-Keynesian models that evaluate economic uncertainties and irregularities might employ nonlinear least squares for certain non-linear predictive models.
Austrian Economics
While traditionally not focused on quantitative approaches, nonlinear least squares can be relevant post facto in testing some Austrian hypotheses through complex agent-based models.
Development Economics
Nonlinear models required to capture nuanced economic growth patterns and country-specific effects frequently apply such techniques for parameter estimation.
Monetarism
Quantitative facets of monetarist frameworks, such as velocity forecasting with non-linear conditions, may deploy nonlinear least squares estimation for precise parameter retrieval.
Comparative Analysis
The nonlinear least squares estimator stands out compared to standard linear estimators due to its adaptability to complex, non-linear models. It requires sophisticated computational techniques but provides more accurate parameter estimations when non-linearity is inherently present in the model.
Case Studies
Several empirical studies have successfully utilized nonlinear least squares estimation. Examples include the estimation of nonlinear consumption functions in Keynesian economics, growth equations in development economics, and various econometric tests and predictive models that inherently involve complex relationships between variables.
Suggested Books for Further Studies
- “Nonlinear Regression Analysis and its Applications” by Douglas M. Bates and Donald G. Watts.
- “Nonlinear Models in Medical Statistics” by James K. Lindsey.
- “Statistical Models: Theory and Practice” by David A. Freedman.
- “The Oxford Handbook on Applied Nonparametric and Semiparametric Econometrics and Statistics” edited by Jeffrey Racine, Liangjun Su, Aman Ullah.
Related Terms with Definitions
- Nonlinear Regression: A form of regression analysis in which observational data is modeled by a function which is a nonlinear combination of the model parameters and depends on one or more independent variables.
- Least Squares Estimation: A method in statistical regression analysis to approximate the solution of over-determined systems by minimizing the sum of the squares of the residuals.
- Parameter Estimation: The process of using sample data to estimate the parameters of the selected model.
